Effect of Carrot Juice on the Texture Properties, Rheology, and Microstructure of Yoghurt

In the present study, carrot juice prepared was added into skimmed milk before fermentation to produce 10% and 20% (w/w) carrot-fortified skim milk. The influence of carrot juice on the lactic acid content, chemical composition, syneresis, texture, rheology property, and microstructure was evaluated along with a potential of carrot juice as an ingredient with rich dietary fiber and a firm structure with interaction of milk protein and a complex matrix under acidification. The results showed that the pH of yoghurt significantly ( P < 0.01 ) reduced with carrot juice addition, minimizing fermentation time by nearly 1 h and brought about an enhanced postacidification during the storage period while titratable acidity increased. Moreover, carrot juice addition had no significant effect on ferric reducing power and phenolic content ( P > 0.05 ). With 10% and 20% level carrot juice added, the total phenolic content (mg GAEkg−1) increased (37.86 and 38.92, respectively) compared with control (36.91) ( P < 0.05 ). Besides, the addition of carrot juice also showed reduced syneresis, increased apparent viscosity and viscoelastic modulus, stable texture, and a refined microstructure. Overall, this study confirmed that carrot juice has a potential as natural and nutrient composition to obtain firm and compact texture and enhance the beneficial quality of yoghurt.